Fair Value (Instruments Not Measured at Fair Value) (Details) - USD ($) $ in Millions		Jun. 30, 2015	Dec. 31, 2014
Carrying Amount [Member]
Assets, Fair Value Disclosure [Abstract]
Accounts receivable - noncurrent	[1]	$ 260	$ 301
Liabilities, Fair Value Disclosure [Abstract]
Non-recourse debt		15,749	15,600
Recourse debt		5,014	5,258
Fair Value [Member]
Assets, Fair Value Disclosure [Abstract]
Value added tax		31	36
Accounts receivable - noncurrent	[1]	247	290
Liabilities, Fair Value Disclosure [Abstract]
Non-recourse debt		16,101	16,008
Recourse debt		5,150	5,552
Level 1 [Member] | Fair Value [Member]
Assets, Fair Value Disclosure [Abstract]
Accounts receivable - noncurrent	[1]	0	0
Liabilities, Fair Value Disclosure [Abstract]
Non-recourse debt		0	0
Recourse debt		0	0
Level 2 [Member] | Fair Value [Member]
Assets, Fair Value Disclosure [Abstract]
Accounts receivable - noncurrent	[1]	0	0
Liabilities, Fair Value Disclosure [Abstract]
Non-recourse debt		12,644	12,538
Recourse debt		5,150	5,552
Level 3 [Member] | Fair Value [Member]
Assets, Fair Value Disclosure [Abstract]
Accounts receivable - noncurrent	[1]	247	290
Liabilities, Fair Value Disclosure [Abstract]
Non-recourse debt		3,457	3,470
Recourse debt		$ 0	$ 0

[1] These accounts receivable principally relate to amounts due from CAMMESA, and are included in Noncurrent assets—Other in the accompanying Condensed Consolidated Balance Sheets. The fair value and carrying amount of these receivables exclude VAT of $31 million and $36 million at June 30, 2015 and December 31, 2014, respectively.